Several old-fashioned and rusty clock faces

Down the Clock

  • A nice variation on classic interval sessions
  • Perfect for the track

Down-the-clock sessions are a good way of adding a bit of variety to interval sessions. By adjusting rep length and recoveries a host of training goals can be achieved.

The Session

A down-the-clock session involves starting with a rep at a certain time or distance, then decreasing the time/distance of each successive rep until a minimum is reached.

By adjusting the length of reps and recoveries a variety of goals can be achieved with down-the-clock sessions.

There are two main benefits that down-the-clock sessions bring. First, starting with a longer rep can help prevent you from starting off too fast, which is often a problem with standard interval sessions. Secondly, knowing that each successive rep will be shorter than the previous can make the session easier psychologically.

They also offer the benefit of variety. The simple fact that they are different from traditional interval sessions, where each rep is the same length, is useful in itself. Variety can help avoid boredom and it's even been suggested that it can help prevent overtraining.


Up the Clock

If you fancy turning the session on its head, then you could try an up-the-clock session instead.

Real World Examples

A good example of a down-the-clock session to work on speed would be to start with a 30-second rep and work in 10-second increments down to a 10-second rep. Since running fast requires one to be well-rested, recoveries should be long. Perhaps as long as 5-6 times rep length. So you'd be taking a three-minute recovery after the 30-second rep and two minutes after the 20-second rep. A complete session could involve 2-3 sets of these with 3-4 minutes of recovery between each set.

A good VO2 Max session could be to start with a 5-minute rep and work in increments of 1 minute down to a 1-minute rep, taking half the rep time as recovery. So, you'd be taking a 2 minute 30 second recovery after the first 5-minute rep, a 2-minute recovery after the 4-minute rep and so on. Following a few minutes of recovery the set could be repeated.


As a general rule you should be keeping a consistent pace for each rep, regardless of length. Try not to speed up as the reps get shorter.

Consider the total volume of running you'll be performing when designing a down-the-clock session. When the reps are different lengths it's easy to lose track and end up doing too much or too little. The best approach is to try and equal the overall volume you would complete in a standard interval session.

It's best to vary recovery according to the length of the previous rep. For speedy sessions, when complete - or almost complete - recovery is important, you'll need more time to recover as rep length increases. For VO2 max sessions, you only want partial recovery between reps, so it's important that recovery is not too long after shorter reps or you will not be getting full benefit.


Remember to warm up before your session and cool down afterwards.